I'm a telecoms engineer that installs fibre and we use red lights to find faults in our telecoms network. The light once shone through can be seen through the fibre at a few kilometers! 👌🏽
I love that fiber optics can use different wavelengths. I hope that our technology becomes so precise that billions of wavelengths can be used on a single line.
@@userunfriendly9304 A single mode fiber usually has an operating range of a couple hundred nanometres already. If the wavelength is too low, higher modes are allowed (limits data rates) and if the wavelength is too large, it won't be guided anymore. You can get "endlessly singlemode" photonic crystal fibers, which have a very wide operating range, but they are stupid expensive. The bigger issue is that glass absorbs the light. You get the lowest absorption at 1310nm and 1550nm, so for long distance you are pretty much limited to those two bands. But thankfully that's more than enough for data transfer. Technically a single wavelength source is enough for insane data speeds, however it's more practical use multiple different wavelengths that are close to 1310 or 1550. With dense wavelength division multiplexing we can currently we can squeeze around 100 channels with 100Gbit/s each into that wavelength range. If you increase the number of channels your maximum data rate per channel will go down as the channels will start to overlap
@@userunfriendly9304 Currently 64 wavelengths are common. It's hard to separate them if the wavelengths are too narrow to each other. You also can't spread too far out, because the reflective index varies with wavelength for the used glass inside. Still impressive. 25 Gbit/s per second on a single wavelength is 1.6TBit/s on a single strand of fibre. One fibre cable can have thousands of strands without getting too bulky.
@@mike1024. Modern fiber is very resilient. I've slammed cabinet doors on them and seen no loss in signal. I'm sure you lose a little, but it's too small for cheap 10gbps optics to measure.
You’ve taught me so much physics and inspired me to take a physics class over the summer which has expanded my knowledge so much and I understand your videos so much better and I understand my other studies better because it’s changed the way I think about things
The speed of light can be slowed down depending on the medium it travels through. This may be a fun concept to look into to further explore light confinement.
Actually refractive index of a medium is nothing but the ratio of speed. Speed of light in air is about 3*10^9 m/sec and in water its speed is 2*10^9m/sec if we divide the speed of light in air by that in water we actually just get the refractive index of water. Diamond has one of the highest refractive index of 2.4. Hence although it slows down the speed of light by 2.4 times ,the speed is still way to high and hence does not make a difference.
With respect to electrical conductors, one thing I found very interesting was that the speed of electrons of AC signals in conductors, has far more to do with what the insulation material is, than what the electrical conductor material is. This phenomena becomes more and more pronounced as the AC signal frequency increases.
The thickness of a fible optic cable core depends on what kind it is. If it is multimode, it is typically 50 microns which is around the thinkness of a human hair. Single mode cables are around 9 microns, a 5th (not a 10th) of a human hair. The closup you show is a thicker multimode one, the one you play with a single mode.
The trouble is light is invisible until it illuminates something visible, and once that's true, light has left the system because it's dispersing everywhere. So even if you successfully trap light in a perfectly reflecting fiber optic cable, it's such a tiny amount length wise that it would require an extremely slow motion camera to witness the exiting light illuminating anything.
light is information/energy and the fiber optic cable does not have much capacity for storing that energy or to put it in other way, its ability to decrease entropy is limited.
@@vaakdemandante8772 damn...I hoped I could replace my ev batttery with a small loop of optic fiber 😀 ok no problem I'll just replace it with electrons in a loop of superconductor 👍superconductor can actually fix the decay of the signal, because there is actually ZERO resistance. but there is a limit for the amps you can pump before the magnetic field breaks the superconducting effect. EDIT funny you can actually store energy as magnetic field in a superconducting coild, but its very low density BUT extremely fast charge/discharge (under a ms)
@@ThunderCat19Dit's an interesting way to exchange energy from one piece of matter to another An excited electron emits a photon which then excites another electron which emits another photon to get back to ground state, etc.
@@frenesisseredsmoker1831 sometimes im seeing bright light sparks with closed eyes when sleeping. I thought that's a bug, but seemingly this is Action Lab turns on his 100000000 lumen flashlight on other side of the planet.
My father developed a method to splice fiber-optic cables back in the early 80s when he was in the Air Force. Prior to that, full replacement was the only option. Because it was while on duty, he could not patent the process. However, he did receive a $10k "Ideas" award for his efforts.
I was hiding behind the couch when you shot that powerful torch into the fibre . I was worried you would send the beam both ways at once and make a particle accelerator, and when the beams met they would produce a black hole and obliterate the earth. But you must have got the angle just perfect to only send it one way. Well done... talk about phew!
During the Apollo missions they left reflectors on the moon. They then shot a laser beam from earth at it to measure the distance to the moon very accurately. What they have effectively done is storing a beam of light for about 2.5 seconds.
A long time ago someone actually suggested that it would be possible to store up to a gigabit of information by modulating the laser beam shot at the Moon, decoding the returned light pulses and resending them immediately. A gigabit was a lot of information at the time😊
@@sitproperlywhilewatchingph423 you send it to the retro reflector on the moon and catch the returning signal, process it and send it out to the moon again.
I've heard that optical cables are also used in high-power laser systems to combine the light of many laser diodes into one, strong one - is this how it's done?
Great demo of the general principles of fibre optics, and the behaviour of optical fibres. I enjoy this channel and hope it has lots of younger followers.
Just a thought that while light is entering the bend in the closed loop, it is also escaping through the same bend. You would need some kind of 1-way photon valve to do a proper test.
Yeah, holding it in the flashlight for prolonged time achieves nothing extra. The moment when bend is straightened again, that's when some photons will be caught bouncing inside, as they don't manage to escape. But that's such a tiny amount, can't be expected to be noticeable to human eye in these tests _even if_ it was not subject to absorption.
I have a question. Please answer if you know. Q. Let assume a mirror circular closed loop of radius 1 cm and put a light source inside it. Now if we On the light source, the light will travel inside the loop. Now if we keep a object of very low mass particle in between the path of light and close that loop, then will that particle experience a force and start moving inside that loop.
I suppose it's a fiber optic cable you use there. In a fiber optic cable the core is surrounded by another similar material that helps reflect the light. I'm studying fiber optics in my IT-Technician course at the moment so I just had to mention that.
It is the experiment I imagined in sixth grade when I was first introduced by optic cables in my computer science class. I think you performed the experiment for me.
That’s what I work with daily. And you even had an SFP. That’s a bend insensitive type of wire meaning it’s less prone to loss with tighter bends. The fibers that travel kilometers are usually not bend insensitive due to cost and usually need to maintain a bend radius not smaller than a pop can. The light that travels through them is IR that is outside the range cameras can see. Some people don’t realize this and look into an open fitting thinking there is visible light. This is dangerous because the light is invisible yet high intensity and at the least will cause permanent blind spots in your eyes. What’s kind of crazy is the connectors must be impeccably clean to minimize loss. For this we use handheld microscopes and tip cleaners. Dust specs even 1/10th of that 1/10th “human hair” sized fiber will cause loss. Which can be easily picked up from air exposure. The style you have with the blue connectors are flat faced tips. The style more commonly being used today are green (apsc) which have slanted faced tips. This is to reduce reflectivity back into the fiber, upstream. Think of it like a window you when look outside. You can see some of your own reflection in the window depending on light conditions. But If look through a window off angle your own image isn’t directed back at you. One of the downsides to slanted connectors though is that when they meet through a bulkhead, they exert the pressure (psi) of the standing foot of an elephant against each other. The slants cause a slight diversion and the 1/10th human hair sized openings on the connectors tend to eclipse each other which is why mechanical connectors (splices) are inherent to more loss than fusion splices.
If the angle required is not too strict, you could design a Y connector that takes light from 2 sources into one outlet, then just loop that outlet into one of the intakes. That way you have one intake free to kick it off and any light will just go on and loop, without the need to connect/disconnect anything.
@@softwarerevolutions first of all, she is alive and her child is younger than me and second, the equipment we had for experiments was made in USSR. I graduated from gymnasium 4 years ago. This concludes that our schools are still broke.
Although it is a fun thought experiment, I think it is pointless to even try for another reason (but also connected to the lightspeed). Not only are the internal losses (cumulatively) so high that the energy dissipates almost instantly after killing the source, but I do believe that you physically cannot close the loop fast enough after shining light into it to even suggest there was a "stream of light circling in the loop (me paraphrasing)". The time you take to straighten out the fiber is something close to eternity in lightspeed terms. So it is safe to say that the optical fiber has gone dark beyond any all-day means of measuring long before you switched the lamp off at 8:26 ....
Always dreamed of "light trapping" but my theory utilized two way mirrors in a tetrahedron type of ball with multiple surfaces reflecting at many different angles. I do like the fiber cable experiment though AND you should visit Lucent Technologies in Georgia to get a longer fiber optic cable.
The speed of light is just unfathomable 😮. Even after so many reflections, and a long fibre cable, the pass through after he connects the laser still seems instantaneous.
Speed itself is unfathomable, since motion is always relative to your point of reference. If the universe is expanding at the speed of light, and you were to pick one point on the edge of the universe and then move towards it at the speed of light, keeping the distance between yourself and the point of reference constant, at which speed are you moving away from the opposite side? Physics hurts my brain. I'm glad I'm just a salesman who needn't worry about such matters.
And in computer therms it is actually really slow, 30cm/ns. In a 10Gb cable, the individual pulses of data are spaced 3cm apart as they move down the cable.
Unassuming channel name, nerdy guy, speaks like he is eating cotton candy. What can you ask more? Much much better than the overrated nile red blah blah and his 'commenters gang'
Light changes speed through different mediums. Not sure if this would even be possible but a hypothetical material that slows down light to a literal crawl. Then you could "capture" some light from one place and let it out somewhere else.
I know something similar to this happens with different kinds of light/electromagnetic waves such as the case with of the waveguide in a microwave oven that guides microwaves into the cooking chamber as well as the ionosphere that enables the long-distance propagation on longwave radio waves such as the ones used in A.M. radios.
Since there’s an “acceptance cone,” ( 3:20 )couldn’t you have one fiber supplying light next to the end of the loop? Would that technically build up how much light was in there?
During the cold war on the West side of the Berlin Wall in remote areas of the wall the U.S. installed a Fiber Optic X,Y grid that was buried in the ground it was used for vehicle detection. The way it worked was that the Fiber Optic cable was laid out in an X,Y grid many meters wide that followed along the wall. The points where the X fiber crossed over the Y fiber was a grid reference point such as X1/Y1, or X10/Y20 , Y50/X32 and so on. The cables had light running through them all the time and the light level that was going in and was coming out of the cables was measured. If a vehicle drove over the cable the compression of the ground caused a reduction of the light level through the intersecting cables at or near the grid points where the vehicle was passing over the cable allowing the location of the vehicle to be determined using the grids closest reference points.
I work as a programmer in a vertical farm company and I was wondering: it is possible to collect light outside a building perhaps by placing these cables on the walls of the building itself to bring it inside directly on the plants?
The reflection is perfect, but as it travels through the bulk of the water there's still a small amount that gets scattered which allows the beam to be seen as it passes the water.
We had really long rolls of optical fiber at work years ago, maybe 50 kilometers. It was unsheathed and spooled in a plastic box so it wasn't that big. We used it for testing fiber communications equipment in a lab with latency like you'd get once installed in the real world. We never tried looping it but I bet the lasers would not have made it around those spools too many times. It'd be detectable with equipment (optical time domain reflectometer) but not visually. Some of the equipment also contained sections of doped fiber that were pumped by a laser of a different wavelength and those could actually amplify the light in the fiber without converting it to an electrical signal first. That would have been interesting to connect in a loop but we didn't. Most long haul laser communications gear will power down the lasers if they don't see a valid signal, that's to protect the eyes of the technician who unplugs the wrong patch fiber and looks at it.
Wow! I knew how fiber optic cables worked but it did not occur to me to “store light” but on second thought I figured it would dissipate at some point because getting 100% percent “efficiency” just seems impossible.
Seems? It genuinely is with our current level of technology, because it breaks the laws of thermodynamics. As with everything else made by human hands, there are expected losses with fiber optics. To send a signal extremely long distances, you need to make use of repeaters placed at equidistant intervals, and the loss of any one of these repeaters will disrupt the signal entirely (they are quite fragile and prone to electromagnetic damage from solar storms apparently). While it is theoretically possible to send a signal through an infinitely long optical cable (say one from an earth base to the moon or a geosynchronous satellite), you'd need an absurd number of repeaters, and it gets exponentially more difficult to keep the signal intact. I'd dare say, it becomes quite impossible after some point, as it's just not practical, nor worthwhile. At current, lasers are being developed and used to handle optical communications at extreme ranges. NASA tested one back in 2021 with the Laser Communications Relay Demonstration (LCRD) mission, and the technology is currently used by Starlink and a few other examples. That said though, he does say that while impossible, the concept still has uses.
we only see the light that has scattered from the laser hitting water molecules. Thats how we can see lasers and so that dosent mean its not reflecting 100%
@@ceray4312 can the way we observe light in waveform be analogues to only being able to see waves on a pond in contrast to the surface only. Just observation and no instruments? Or should I begin a medication regiment?
@@pierrelabrecque8979 tbh I dont really understand what you mean by 'surface only', but firstly we dont see the waveform of light with just our eyes and secondly whether light is a wave or particle is up to debate (look up double slit experiment) so its not like water
My ISP literally just routed a naked optic fiber into my apartment, hot-glued it directly onto the wall and around the doors, and plugged it in, no shielding whatsoever, it also has a bend like the one you made hardwired into the receiver piece AND my cat chewed on it a few times with visible damage to the core haha, but miraculously I have a working gigabit connection and no latency issues etc.
I've always wanted to build my own home and use even cheaper plastic fiber optics that run from outside my house to the basement and center of the home to give off light during the day. Always thought how cool it would be to light up my house with the sun rather than electricity. And as i typed this, i thought why not have a centralized light source that can be "dampened" rather than individual lights in every room. Anyways, friday night thoughts are done. lol
There's a town in Norway I think that's entirely in the shadow of a mountain for most of the year, they've placed giant mirrors to shine sunlight on the central square because mental health of inhabitants was negatively affected by the constant shadow
In college in the 90s I had a broadcast TV production class with TV cameras like a news studio. They had thick fiber optic cables going from the camera to the control room. The teacher was like "Please don't step on those cables, they have about a thousand fiber optics inside and if one breaks I have to check them one by one". I assume he was exaggerating.
Even if the trapped light did not dissipate, you would only see a few nano seconds of it when you let it out. So you probably could not see it anyways without a really really high speed camera.
I get my internet from a small neighborhood ISP whom I worked with for a short period of time. One time he was checking a fiber optic cable to see if it works: He took out an end from his device and plugged it into a little laser then put it on his desk, afterward we both got in the car and drove many streets away to a rather far location, he climbed on the pole took down a connection unwrapped the cables and started looking... there it was, the blinking red light on the other end. I found it fascinating to think how a small battery powered laser in the building far away was shining through a wire far away, it made perfect sense but felt like magic at the same time.
Awesome thought experiment! i learned two things - why fiber needs to have repeater/amplifiers every several km, and - most importantly, i can purchase a device that will turn my 60+y old face, into someone only 20! its an awesome day, today! (seriously, i always enjoy your video's! it is so exciting for every youth - for me, it was transistors at they time they replaced vacuum tubes/valves! God bless you!
1LT: "Hey guys! Whatcha doin'?" SSG: "Oohh, we're just charging the photon filaments in the fiber-optic cables." 1LT: "Wow! That's so high-speed! Keep up the good work!"
Reminds me of a concept called "slow glass" from an old Sci-fi series of short stories (Bob Shaw). Basically it took decades for the light to travel through the glass, so people used them to replace their windows.
Fiber optic cables are used in transferring audio from the source to an input device like a surround receiver which decodes the light into an audio signal and then the receiver sends the audio to the amplifier portion of the surround sound receiver which is then sent to its corresponding speaker but down side is optical audio is limited to 5.1, if you want 7.1, 5.1.2, or any other form of atmos/dtsx you have to use hdmi but as far as 5.1 optical is fine!
This reminds me of a Finnish children's story about a family of fools. They built a house without any windows and tried to solve the problem by trapping sunlight into a bag and carry it in to the house.
They already stored light back in 2013 using a cryogenically cooled opaque crystal of yttrium silicate doped with praseodymium. One control laser shining on it made the crystal transparent to light, another laser shone through the crystal was then turned on, after which, the control laser was turned off, returning the crystal to an opaque state, effectively "freezing" the light inside, then turning off the second laser. Turning the crystal transparent again allowed the crystal to release the light as if the second laser was shining through. It could maintain the coherence for about a minute before fizzling.
Phosphorescent materials, known as glow in the dark pigments, are the answer to the question at the end of the video. They absorb light at a short wavelength and emit it at a longer wavelength that they shouldn't be able to, so the light they should emit is trapped and leaking out slowly due to quantum effects.
Admirable differentiation between the two terms "Fibre Optics", a scientific discipline, and "Optical Fibre" a physical object. too many people are sloppy with these terms. (Sorry, one of my pet hates :-)
When computer engineering was nascent, they used delay lines as working memory. One stores info by making sound pulses into one end of a tube filled with liquid mercury. At the end of the tube, transducers convert the acoustic pulses to electric, which are channelled back to the start of the tube. Info keeps recirculating until you want to use it. Then you read it, modify it, and send the result back down the tube. In my case, we send optical pulses down a fiber, collect it at end, which happens to be near the start, and use it there. Oops, DRAMS and SRAMS act faster than 1ns/foot (~c).
This also reminded me of Dr. Mallet's time machine made of looping laser light (it supposed to 'stir up' spacetime enought to connect the moment machine has been turned on with the present moment...).
Yep. Businesses started paying big money to store their computer systems as close to the exchange as possible. Also paying to make sure the fibre to the exchange was as straight as possible. The crazy things greed will cause people to come up with.
Graded index of the fiber keeps the light in, meaning the density of the glass changes from the center outwards, it was designed like that on purpose. If the light goes in at an angle and straight, that graded index of density will cause the light to bend basically in a sinusoidal fashion.
2:55 What's interesting is that because it's bouncing back and forth throughout the firer-optic cable, the photons are traveling a longer total distance than the length of the cable. Granted, the diameter of the glass is very small, but so is the wavelength of the photon, so it bounces a LOT by the time it comes out the other end, so it quickly adds up so that the photon ends up traveling a SIGNIFICANT distance more than the length of the cable, which over longer distances, can actually outpace the speed of light and cause latency and has to be accounted for. If there's TOTAL reflection, then why do fiber-optic cables require boosters? 🤨 … 8:57 That's the ticket, laddie. 4:45 It looks like the fiber is heating up from being bent. 😀 That's actually a useful property for diagnostics. 4:59 You're describing the end of _Hellraiser IV: Bloodlines._ 😉 5:47 Another option is to inject the light into a VERY LONG cable that's long enough that it takes the light a second or two to reach the end. 10:07 So… Pinhead WASN'T defeated? WHAAAA-‽ 😲
Fabry Pérot! I ve been working on table-top experiments, with cavity photon lifetimes below the microsecond scale, but in fact, they are people doing much better, eg in the LIGO/VIRGO interferometer, I don t have the numbers on top of my mind but the recycling system, together with 3 or 4 km arms, has I would say photon lifetimes on the order of 10 ms, that would make it visible to naked eye! Cheers and thanks for the video
Video idea: trapping electric currents in superconducting wires. Electrons flow without resistance in superconductors, so electron *should* travel around a looping cable of superconducting material for as long as the superconductivity lasts.
The best way to store light basically indefinitely (without converting it) is a black hole. Right above the event horizon light will be bend on a on a perfect circle orbit around the black hole. As long as it doesn't hit any material in space, which there is not a lot of, if the BH has no accretion disc, it can stay there for quite a long while.
You showed us the most reflective sheet of plastic(? Dielectric mirror) You can wrap it around. Or in the current settings try using 2 cameras in a dark room. Use first one while shining the light into the fiber optic cable(the whole cable or one side instead of a single strand) and the second one right after turning off the flashlight as the camera takes time to auto-adjust the aperture, try keeping the lens covered until the 2nd part.
I'm a telecoms engineer that installs fibre and we use red lights to find faults in our telecoms network. The light once shone through can be seen through the fibre at a few kilometers! 👌🏽
I love that fiber optics can use different wavelengths. I hope that our technology becomes so precise that billions of wavelengths can be used on a single line.
@@userunfriendly9304 A single mode fiber usually has an operating range of a couple hundred nanometres already. If the wavelength is too low, higher modes are allowed (limits data rates) and if the wavelength is too large, it won't be guided anymore. You can get "endlessly singlemode" photonic crystal fibers, which have a very wide operating range, but they are stupid expensive.
The bigger issue is that glass absorbs the light. You get the lowest absorption at 1310nm and 1550nm, so for long distance you are pretty much limited to those two bands. But thankfully that's more than enough for data transfer. Technically a single wavelength source is enough for insane data speeds, however it's more practical use multiple different wavelengths that are close to 1310 or 1550. With dense wavelength division multiplexing we can currently we can squeeze around 100 channels with 100Gbit/s each into that wavelength range. If you increase the number of channels your maximum data rate per channel will go down as the channels will start to overlap
wow super interesting!
What the heck is a fiber engineer?
@@userunfriendly9304 Currently 64 wavelengths are common. It's hard to separate them if the wavelengths are too narrow to each other. You also can't spread too far out, because the reflective index varies with wavelength for the used glass inside.
Still impressive. 25 Gbit/s per second on a single wavelength is 1.6TBit/s on a single strand of fibre. One fibre cable can have thousands of strands without getting too bulky.
I thought the reason why we shouldn't bend the fiber optic cable too much is because the glass inside would snap
that too!
I was actually amazed that the glass didn't snap, but I guess it was much thinner than other fiber-optic cables I've encountered in the past.
@@mike1024. Modern fiber is very resilient. I've slammed cabinet doors on them and seen no loss in signal. I'm sure you lose a little, but it's too small for cheap 10gbps optics to measure.
@@NavinF Good to know! I haven't looked at a fiberoptic cable in several years.
@@NavinFThe phrase "cheap 10gbps optics" sent me into a time warp and made me realize that we live in the future
I love how this channel brings a sense of whimsy to science. Thank you for your material!
The pseudoscience and science fiction in this channel is very whimsical indeed. The scam product sponsorship was the cherry on top, lol
@@weblureSponsorblock. It made youtube watchable again instead of endless pitches for Nord Shark Shadows Mafia Legends
Surprising that you didn't mention Lene Hau at all. In 2001 she became the first person to stop light completely, using a Bose Einstein Condensate.
stop light from what?
I can stop light completely too... using a light switch....
Thank you, fascinating experiment.
@@michelletadmor8642 not just stopping.. she made it go at 17 m/s...
Did she close her eyes?
You’ve taught me so much physics and inspired me to take a physics class over the summer which has expanded my knowledge so much and I understand your videos so much better and I understand my other studies better because it’s changed the way I think about things
The speed of light can be slowed down depending on the medium it travels through. This may be a fun concept to look into to further explore light confinement.
Actually refractive index of a medium is nothing but the ratio of speed.
Speed of light in air is about 3*10^9 m/sec and in water its speed is 2*10^9m/sec
if we divide the speed of light in air by that in water we actually just get the refractive index of water.
Diamond has one of the highest refractive index of 2.4.
Hence although it slows down the speed of light by 2.4 times ,the speed is still way to high and hence does not make a difference.
I like to explore a little light confinement now and then. 🔗 🔒 😉
But won’t a slower speed of light mean more energy lost per meter traveled?
With respect to electrical conductors, one thing I found very interesting was that the speed of electrons of AC signals in conductors, has far more to do with what the insulation material is, than what the electrical conductor material is. This phenomena becomes more and more pronounced as the AC signal frequency increases.
You can't slow down the speed of light because its constant. You can only make it go a longer path
The thickness of a fible optic cable core depends on what kind it is. If it is multimode, it is typically 50 microns which is around the thinkness of a human hair. Single mode cables are around 9 microns, a 5th (not a 10th) of a human hair. The closup you show is a thicker multimode one, the one you play with a single mode.
except that's just the core, the fiber also has cladding, bringing the OD to 125 microns for both multi and single mode...
@@AKAtheA yes, like I specify in the first sentence XD
Bro stopped reading 7 words in lmao
Is that why at 3:05 light is in two bright spots on the output of the cable? Is that a cross-section of the intensity of the propagating mode?
@@WouterVerbruggennooit gedacht hier een nederlander tegen te komen
The trouble is light is invisible until it illuminates something visible, and once that's true, light has left the system because it's dispersing everywhere.
So even if you successfully trap light in a perfectly reflecting fiber optic cable, it's such a tiny amount length wise that it would require an extremely slow motion camera to witness the exiting light illuminating anything.
light is information/energy and the fiber optic cable does not have much capacity for storing that energy or to put it in other way, its ability to decrease entropy is limited.
@@vaakdemandante8772 damn...I hoped I could replace my ev batttery with a small loop of optic fiber 😀 ok no problem I'll just replace it with electrons in a loop of superconductor 👍superconductor can actually fix the decay of the signal, because there is actually ZERO resistance. but there is a limit for the amps you can pump before the magnetic field breaks the superconducting effect.
EDIT funny you can actually store energy as magnetic field in a superconducting coild, but its very low density BUT extremely fast charge/discharge (under a ms)
So a sort of water isn't wet water makes things wet. Light isn't light it illuminates things.
@@ThunderCat19Dit's an interesting way to exchange energy from one piece of matter to another
An excited electron emits a photon which then excites another electron which emits another photon to get back to ground state, etc.
extremely is an understatement 😂
Action lab never fails to entertain and "enlighten" me 😀
This pun brightened my day
If i had a "sun" he would love that pun
Edit: ooh a rhyme
@@frenesisseredsmoker1831 sometimes im seeing bright light sparks with closed eyes when sleeping. I thought that's a bug, but seemingly this is Action Lab turns on his 100000000 lumen flashlight on other side of the planet.
You are the science teacher that I needed in high school. Love your videos!
Amen - Amen! and collage as well- he is a perfect model for how teaching should be approached.
My father developed a method to splice fiber-optic cables back in the early 80s when he was in the Air Force. Prior to that, full replacement was the only option. Because it was while on duty, he could not patent the process. However, he did receive a $10k "Ideas" award for his efforts.
Should've quit his job and patent. Would been a millionaire
@@DeezNutz-ce5se you can't just quit the military.
@@awgunner429you can hide your invention and patent it later.
@@awgunner429 Then he should've kept the idea to himself until he was out of the military.
10k in the 80's isn't a small amount, but JESUS, he still got ripped off so hard.
5:42 when people who didn't know this expected to see you do it physically ☠☠
I thought you would make a 3-way adapter to "inject" the light, but hitting that critical angle might be hard. Oh well🤷🏽♂️
I was hiding behind the couch when you shot that powerful torch into the fibre .
I was worried you would send the beam both ways at once and make a particle accelerator, and when the beams met they would produce a black hole and obliterate the earth.
But you must have got the angle just perfect to only send it one way.
Well done... talk about phew!
During the Apollo missions they left reflectors on the moon. They then shot a laser beam from earth at it to measure the distance to the moon very accurately. What they have effectively done is storing a beam of light for about 2.5 seconds.
A long time ago someone actually suggested that it would be possible to store up to a gigabit of information by modulating the laser beam shot at the Moon, decoding the returned light pulses and resending them immediately. A gigabit was a lot of information at the time😊
@@nkronertso storing the info by sending it back and forth ?
@@sitproperlywhilewatchingph423 you send it to the retro reflector on the moon and catch the returning signal, process it and send it out to the moon again.
@@nkronert that's the principal behind harder drives; they use wifi signals bouncing around the atmosphere to store information
@@person8064 can you elaborate on that please? I've not heard of this before.
I've heard that optical cables are also used in high-power laser systems to combine the light of many laser diodes into one, strong one - is this how it's done?
Great demo of the general principles of fibre optics, and the behaviour of optical fibres. I enjoy this channel and hope it has lots of younger followers.
Holy crap! I've been theorizing for a few years about sending light through a coil, in a loop.
This method could actually do it!
You missed inventing this technology by about half a century. The first fiber optic cable was invented in the 1950's.
The idea of trapping light in a mirror room has toyed with my mind since I was about 8 years old. This video MADE MY DAY!
Research Kurt Vonnegut's "LEAKS"
Just a thought that while light is entering the bend in the closed loop, it is also escaping through the same bend. You would need some kind of 1-way photon valve to do a proper test.
Yeah, holding it in the flashlight for prolonged time achieves nothing extra.
The moment when bend is straightened again, that's when some photons will be caught bouncing inside, as they don't manage to escape. But that's such a tiny amount, can't be expected to be noticeable to human eye in these tests _even if_ it was not subject to absorption.
I have a question. Please answer if you know.
Q. Let assume a mirror circular closed loop of radius 1 cm and put a light source inside it. Now if we On the light source, the light will travel inside the loop. Now if we keep a object of very low mass particle in between the path of light and close that loop, then will that particle experience a force and start moving inside that loop.
Great video !
I've worked with fibre cables for many years, but not seen some of the things you demonstrated today before.
I suppose it's a fiber optic cable you use there. In a fiber optic cable the core is surrounded by another similar material that helps reflect the light. I'm studying fiber optics in my IT-Technician course at the moment so I just had to mention that.
It is the experiment I imagined in sixth grade when I was first introduced by optic cables in my computer science class. I think you performed the experiment for me.
That’s what I work with daily. And you even had an SFP. That’s a bend insensitive type of wire meaning it’s less prone to loss with tighter bends. The fibers that travel kilometers are usually not bend insensitive due to cost and usually need to maintain a bend radius not smaller than a pop can. The light that travels through them is IR that is outside the range cameras can see. Some people don’t realize this and look into an open fitting thinking there is visible light. This is dangerous because the light is invisible yet high intensity and at the least will cause permanent blind spots in your eyes. What’s kind of crazy is the connectors must be impeccably clean to minimize loss. For this we use handheld microscopes and tip cleaners. Dust specs even 1/10th of that 1/10th “human hair” sized fiber will cause loss. Which can be easily picked up from air exposure. The style you have with the blue connectors are flat faced tips. The style more commonly being used today are green (apsc) which have slanted faced tips. This is to reduce reflectivity back into the fiber, upstream. Think of it like a window you when look outside. You can see some of your own reflection in the window depending on light conditions. But If look through a window off angle your own image isn’t directed back at you. One of the downsides to slanted connectors though is that when they meet through a bulkhead, they exert the pressure (psi) of the standing foot of an elephant against each other. The slants cause a slight diversion and the 1/10th human hair sized openings on the connectors tend to eclipse each other which is why mechanical connectors (splices) are inherent to more loss than fusion splices.
If the angle required is not too strict, you could design a Y connector that takes light from 2 sources into one outlet, then just loop that outlet into one of the intakes. That way you have one intake free to kick it off and any light will just go on and loop, without the need to connect/disconnect anything.
I wondered about this also!
Im a network consultant so much of this is Knowledge ive already got, but wow, I never thought to test an SFP with a multimeter! Very good idea!
You explained this concept better than my physics teacher did when I went to school.
RIP physics teacher
@@softwarerevolutions first of all, she is alive and her child is younger than me and second, the equipment we had for experiments was made in USSR. I graduated from gymnasium 4 years ago. This concludes that our schools are still broke.
Although it is a fun thought experiment, I think it is pointless to even try for another reason (but also connected to the lightspeed). Not only are the internal losses (cumulatively) so high that the energy dissipates almost instantly after killing the source, but I do believe that you physically cannot close the loop fast enough after shining light into it to even suggest there was a "stream of light circling in the loop (me paraphrasing)". The time you take to straighten out the fiber is something close to eternity in lightspeed terms. So it is safe to say that the optical fiber has gone dark beyond any all-day means of measuring long before you switched the lamp off at 8:26 ....
Don't switch the lamp off then...just keep the light shining and release the bend. Might that work?
Always dreamed of "light trapping" but my theory utilized two way mirrors in a tetrahedron type of ball with multiple surfaces reflecting at many different angles. I do like the fiber cable experiment though AND you should visit Lucent Technologies in Georgia to get a longer fiber optic cable.
Love what ur doing with changing the thumbnail to see the results vs the original
The speed of light is just unfathomable 😮. Even after so many reflections, and a long fibre cable, the pass through after he connects the laser still seems instantaneous.
Speed itself is unfathomable, since motion is always relative to your point of reference. If the universe is expanding at the speed of light, and you were to pick one point on the edge of the universe and then move towards it at the speed of light, keeping the distance between yourself and the point of reference constant, at which speed are you moving away from the opposite side?
Physics hurts my brain. I'm glad I'm just a salesman who needn't worry about such matters.
And in computer therms it is actually really slow, 30cm/ns. In a 10Gb cable, the individual pulses of data are spaced 3cm apart as they move down the cable.
Light can travel 7.48 times around the entire earth in a loop in 1 second.
And yet it’s so slow when you start to zoom out to astronomical scales.
Yes, it takes millions and millions of years to reach from the furthest corners of our universe. FTL travel is the holy grail of science fiction.
One of my favourite channels. Thanks for your content.
Unassuming channel name, nerdy guy, speaks like he is eating cotton candy. What can you ask more? Much much better than the overrated nile red blah blah and his 'commenters gang'
Light changes speed through different mediums. Not sure if this would even be possible but a hypothetical material that slows down light to a literal crawl. Then you could "capture" some light from one place and let it out somewhere else.
Isn't that exactly what Lene Hau did?
@@BriShep123 No clue, that's a name I've never heard before, but you've given me something interesting to research.
Trapping light in a fiber cable loop was invented by the guy that proved the fridge light stays on when the door is closed.
I know something similar to this happens with different kinds of light/electromagnetic waves such as the case with of the waveguide in a microwave oven that guides microwaves into the cooking chamber as well as the ionosphere that enables the long-distance propagation on longwave radio waves such as the ones used in A.M. radios.
I like how you also actually explained the technology behind the sponsor's product, you know your audience!
We learn about refraction and TIR in class 7th or 8th in India
But saw the fibre for the first time like this..... beautiful ❤
You're sharing basic science from 100 years ago with the public. Nice.
Since there’s an “acceptance cone,” ( 3:20 )couldn’t you have one fiber supplying light next to the end of the loop? Would that technically build up how much light was in there?
Yup I believe that should work, good idea for a follow up video
❤you can tell your viewers are passionate about physical science and accuracy, and that you encourage thought and discourse❤
4:30 makes me think you might be able to see a faint glow from the coil of fiber if you look at it in a completely dark room.
You can, though those thick jacket fibers block it pretty well. With the thinner 900um jacket fibers it's much more visible.
During the cold war on the West side of the Berlin Wall in remote areas of the wall the U.S. installed a Fiber Optic X,Y grid that was buried in the ground it was used for vehicle detection. The way it worked was that the Fiber Optic cable was laid out in an X,Y grid many meters wide that followed along the wall. The points where the X fiber crossed over the Y fiber was a grid reference point such as X1/Y1, or X10/Y20 , Y50/X32 and so on. The cables had light running through them all the time and the light level that was going in and was coming out of the cables was measured. If a vehicle drove over the cable the compression of the ground caused a reduction of the light level through the intersecting cables at or near the grid points where the vehicle was passing over the cable allowing the location of the vehicle to be determined using the grids closest reference points.
I had the exact question of can we capture light, thanks for such an awesome video!
I work as a programmer in a vertical farm company and I was wondering:
it is possible to collect light outside a building
perhaps by placing these cables on the walls of the building itself
to bring it inside directly on the plants?
wow!
How can it be “perfect” reflection in water, glass, etc if you can see it? Wouldn’t that still mean there’s losses and it’s less than 100%?
The reflection is perfect, but as it travels through the bulk of the water there's still a small amount that gets scattered which allows the beam to be seen as it passes the water.
Reflection total 100% but the water is scattering the light and changing its parth as a result you see light beam
The surface is perfectly reflective. Where is the light coming from and ending up? Hope this answers your question.
3:05 Why is the output light in two bright spots like this? Could it be due to some kind of modal propagation inside the fiber?
Could be the design of the laser itself.
Love your videos❤️❤️❤️
We had really long rolls of optical fiber at work years ago, maybe 50 kilometers. It was unsheathed and spooled in a plastic box so it wasn't that big. We used it for testing fiber communications equipment in a lab with latency like you'd get once installed in the real world. We never tried looping it but I bet the lasers would not have made it around those spools too many times. It'd be detectable with equipment (optical time domain reflectometer) but not visually.
Some of the equipment also contained sections of doped fiber that were pumped by a laser of a different wavelength and those could actually amplify the light in the fiber without converting it to an electrical signal first. That would have been interesting to connect in a loop but we didn't. Most long haul laser communications gear will power down the lasers if they don't see a valid signal, that's to protect the eyes of the technician who unplugs the wrong patch fiber and looks at it.
Wow! I knew how fiber optic cables worked but it did not occur to me to “store light” but on second thought I figured it would dissipate at some point because getting 100% percent “efficiency” just seems impossible.
Seems? It genuinely is with our current level of technology, because it breaks the laws of thermodynamics. As with everything else made by human hands, there are expected losses with fiber optics. To send a signal extremely long distances, you need to make use of repeaters placed at equidistant intervals, and the loss of any one of these repeaters will disrupt the signal entirely (they are quite fragile and prone to electromagnetic damage from solar storms apparently). While it is theoretically possible to send a signal through an infinitely long optical cable (say one from an earth base to the moon or a geosynchronous satellite), you'd need an absurd number of repeaters, and it gets exponentially more difficult to keep the signal intact. I'd dare say, it becomes quite impossible after some point, as it's just not practical, nor worthwhile.
At current, lasers are being developed and used to handle optical communications at extreme ranges. NASA tested one back in 2021 with the Laser Communications Relay Demonstration (LCRD) mission, and the technology is currently used by Starlink and a few other examples.
That said though, he does say that while impossible, the concept still has uses.
Your topic matter is beyond amazing. I find it makes me ponder things I'd never even considered.
If 100% of the light is reflected off the surface of the water, we wouldn't be able to see it from above.
we only see the light that has scattered from the laser hitting water molecules. Thats how we can see lasers and so that dosent mean its not reflecting 100%
We would not be able to see the laser in that case.
@@ceray4312 can the way we observe light in waveform be analogues to only being able to see waves on a pond in contrast to the surface only. Just observation and no instruments? Or should I begin a medication regiment?
I think it's called Tyndall effect
@@pierrelabrecque8979 tbh I dont really understand what you mean by 'surface only', but firstly we dont see the waveform of light with just our eyes and secondly whether light is a wave or particle is up to debate (look up double slit experiment) so its not like water
My ISP literally just routed a naked optic fiber into my apartment, hot-glued it directly onto the wall and around the doors, and plugged it in, no shielding whatsoever, it also has a bend like the one you made hardwired into the receiver piece AND my cat chewed on it a few times with visible damage to the core haha, but miraculously I have a working gigabit connection and no latency issues etc.
My Fish Aquarium always does this, and its really bright.
but it would only fully reflect from the surface of the water
"I don't know if you've heard this already, but light moves really fast." ❤😂
I've always wanted to build my own home and use even cheaper plastic fiber optics that run from outside my house to the basement and center of the home to give off light during the day. Always thought how cool it would be to light up my house with the sun rather than electricity. And as i typed this, i thought why not have a centralized light source that can be "dampened" rather than individual lights in every room. Anyways, friday night thoughts are done. lol
This is worth watching a video on :D Anyone know of cases where fiber-optics are used with the sun being the light source?
@@BimotaMoon You'd need a lot of cables to cover enough area to light up a room, and at that point, why not just use a solar panel?
There's a town in Norway I think that's entirely in the shadow of a mountain for most of the year, they've placed giant mirrors to shine sunlight on the central square because mental health of inhabitants was negatively affected by the constant shadow
how about storing light in layers of phosphorescent material?
On top of being an incredibly informative and brilliantly interesting video as everyone of your videos always are that BEAR device is cool beans!
In college in the 90s I had a broadcast TV production class with TV cameras like a news studio. They had thick fiber optic cables going from the camera to the control room. The teacher was like "Please don't step on those cables, they have about a thousand fiber optics inside and if one breaks I have to check them one by one". I assume he was exaggerating.
Even if the trapped light did not dissipate, you would only see a few nano seconds of it when you let it out. So you probably could not see it anyways without a really really high speed camera.
What about the Slo Mo Guys then ?
A detector would be more effective in this case... (just now realizing thats all cameras are... photon detectors)
Maybe a pulse yag laser doubled to green. That’s a megawatt for a few nanoseconds per pulse.
I get my internet from a small neighborhood ISP whom I worked with for a short period of time. One time he was checking a fiber optic cable to see if it works: He took out an end from his device and plugged it into a little laser then put it on his desk, afterward we both got in the car and drove many streets away to a rather far location, he climbed on the pole took down a connection unwrapped the cables and started looking... there it was, the blinking red light on the other end. I found it fascinating to think how a small battery powered laser in the building far away was shining through a wire far away, it made perfect sense but felt like magic at the same time.
6:28 there was no need to show the video of your last colonoscopy... 😉
Awesome thought experiment! i learned two things - why fiber needs to have repeater/amplifiers every several km, and - most importantly, i can purchase a device that will turn my 60+y old face, into someone only 20! its an awesome day, today! (seriously, i always enjoy your video's! it is so exciting for every youth - for me, it was transistors at they time they replaced vacuum tubes/valves! God bless you!
hello everybody my name is Markiplier
Wow that's actually amazing that it's generating a voltage with the transceiver and nothing else. Light really is something else.
That's very important to have a best idea of total internal reflection.
One of my friend's dad is a fiber optic worker and one time he let us learn and fuse the glass. It was way cool.
1LT: "Hey guys! Whatcha doin'?"
SSG: "Oohh, we're just charging the photon filaments in the fiber-optic cables."
1LT: "Wow! That's so high-speed! Keep up the good work!"
Thanks for the great explanation. I’ve always found fiber optics fascinating.
Great optical fiber cable introduction
"I don't know if you heard this already, but light moves very fast"🤯
"I don't know if you've heard this already but light moves very fast" -Action Lab 2023
Reminds me of a concept called "slow glass" from an old Sci-fi series of short stories (Bob Shaw).
Basically it took decades for the light to travel through the glass, so people used them to replace their windows.
Fiber optic cables are used in transferring audio from the source to an input device like a surround receiver which decodes the light into an audio signal and then the receiver sends the audio to the amplifier portion of the surround sound receiver which is then sent to its corresponding speaker but down side is optical audio is limited to 5.1, if you want 7.1, 5.1.2, or any other form of atmos/dtsx you have to use hdmi but as far as 5.1 optical is fine!
2:39 Oh my word, that's cool AF. That's basically how fibre optic internet works only there's a converter on either end 😯🤯😃
Bloody wicked that is 😊
LoL tomorrow I have physics exam and question on these topics is going to be asked. What a perfect timing this video landed on RUclips!
Could you use that to see the speed of light if you just had a long enough roll of that cable?
This reminds me of a Finnish children's story about a family of fools. They built a house without any windows and tried to solve the problem by trapping sunlight into a bag and carry it in to the house.
Absolutely LOVE the shirt!
They already stored light back in 2013 using a cryogenically cooled opaque crystal of yttrium silicate doped with praseodymium. One control laser shining on it made the crystal transparent to light, another laser shone through the crystal was then turned on, after which, the control laser was turned off, returning the crystal to an opaque state, effectively "freezing" the light inside, then turning off the second laser. Turning the crystal transparent again allowed the crystal to release the light as if the second laser was shining through. It could maintain the coherence for about a minute before fizzling.
Phosphorescent materials, known as glow in the dark pigments, are the answer to the question at the end of the video. They absorb light at a short wavelength and emit it at a longer wavelength that they shouldn't be able to, so the light they should emit is trapped and leaking out slowly due to quantum effects.
ok so you said at 0:28 that at the critical angle water becomes a perfect mirror so could you use water to forever bounce light around?
Admirable differentiation between the two terms "Fibre Optics", a scientific discipline, and "Optical Fibre" a physical object. too many people are sloppy with these terms. (Sorry, one of my pet hates :-)
When computer engineering was nascent, they used delay lines as working memory. One stores info by making sound pulses into one end of a tube filled with liquid mercury. At the end of the tube, transducers convert the acoustic pulses to electric, which are channelled back to the start of the tube. Info keeps recirculating until you want to use it. Then you read it, modify it, and send the result back down the tube. In my case, we send optical pulses down a fiber, collect it at end, which happens to be near the start, and use it there. Oops, DRAMS and SRAMS act faster than 1ns/foot (~c).
This also reminded me of Dr. Mallet's time machine made of looping laser light (it supposed to 'stir up' spacetime enought to connect the moment machine has been turned on with the present moment...).
On the note of adding delays- you should add a reference of the NYSE. They use a very long piece of fiber for purposely delaying signals.
How long and how much of a delay?
@@warlockpaladin2261 Enough to even out the playing field. 😉
It was originally copper, I believe.
@@warlockpaladin226161km. 350 microseconds delay. It's nicknamed the Magic Shoebox.
Yep. Businesses started paying big money to store their computer systems as close to the exchange as possible. Also paying to make sure the fibre to the exchange was as straight as possible.
The crazy things greed will cause people to come up with.
"AH HA, I'VE DONE IT, I'VE TRAPPED LIGHT IN AND ENDLESS REFLECTIVE LOOP!"
"Cool, can we see it?"
"Well... no."
I work with fiber cable too. Each splice or termination introduces loss and reflections. Much more than a long section of cable.
I like how you wiggled the bend in the fibre optic cable to make sure the photons would enter it
Graded index of the fiber keeps the light in, meaning the density of the glass changes from the center outwards,
it was designed like that on purpose. If the light goes in at an angle and straight,
that graded index of density will cause the light to bend basically in a sinusoidal fashion.
2:55 What's interesting is that because it's bouncing back and forth throughout the firer-optic cable, the photons are traveling a longer total distance than the length of the cable. Granted, the diameter of the glass is very small, but so is the wavelength of the photon, so it bounces a LOT by the time it comes out the other end, so it quickly adds up so that the photon ends up traveling a SIGNIFICANT distance more than the length of the cable, which over longer distances, can actually outpace the speed of light and cause latency and has to be accounted for.
If there's TOTAL reflection, then why do fiber-optic cables require boosters? 🤨 … 8:57 That's the ticket, laddie.
4:45 It looks like the fiber is heating up from being bent. 😀 That's actually a useful property for diagnostics.
4:59 You're describing the end of _Hellraiser IV: Bloodlines._ 😉
5:47 Another option is to inject the light into a VERY LONG cable that's long enough that it takes the light a second or two to reach the end.
10:07 So… Pinhead WASN'T defeated? WHAAAA-‽ 😲
@ 6:25 I'm so glad that's your hand.
The person who will discover something 100% reflective will create the future as we’ll finally have something to store electricity efficiently
Fabry Pérot! I ve been working on table-top experiments, with cavity photon lifetimes below the microsecond scale, but in fact, they are people doing much better, eg in the LIGO/VIRGO interferometer, I don t have the numbers on top of my mind but the recycling system, together with 3 or 4 km arms, has I would say photon lifetimes on the order of 10 ms, that would make it visible to naked eye! Cheers and thanks for the video
the fact that you can see the light on the outside, itself disproves the claim of trapping light
Video idea: trapping electric currents in superconducting wires. Electrons flow without resistance in superconductors, so electron *should* travel around a looping cable of superconducting material for as long as the superconductivity lasts.
Interesting video, James, thanks!
Know what I'd love to see? A cable 186k miles long, culed up, so that if you shine light in one end, you'll see it come out the other a second later.
Problem is you would need a lot of repeaters and amplifiers. So it wouldn’t be the “same” photons.
@@MeppyMan good point
The best way to store light basically indefinitely (without converting it) is a black hole. Right above the event horizon light will be bend on a on a perfect circle orbit around the black hole. As long as it doesn't hit any material in space, which there is not a lot of, if the BH has no accretion disc, it can stay there for quite a long while.
You showed us the most reflective sheet of plastic(? Dielectric mirror) You can wrap it around. Or in the current settings try using 2 cameras in a dark room. Use first one while shining the light into the fiber optic cable(the whole cable or one side instead of a single strand) and the second one right after turning off the flashlight as the camera takes time to auto-adjust the aperture, try keeping the lens covered until the 2nd part.